#include<iostream>

using namespace std;

int Max(int a, int b) {
    if (a > b)return a;
    else return b;
}

int Max4(int a, int b, int c, int d) {
    int ret = Max(a, b);//res(ult)  ret(urn) ans(wer)
    ret = Max(ret, c);
    ret = Max(ret, d);
    return ret;
}

int main() {
    cout << Max4(3, 4, 5, 6) << endl;
    return 0;
}
